This is a revised application of RR12924, initially submitted on March 20, 1997. We thank the reviewer for pointing out the strengths ("well- written and strong organizational plan") and weaknesses ("insufficient availability of instrument time to 10 investigators and lack of justification in some projects to acquire BIAcore 2000"). We have clearly responded to the criticisms and incorporated them in this amended application. We have reduced the number of co-investigators from 10 to 6 focusing on investigators with the greatest need for the BIAcore 2000 in their research projects. This change will clearly allow sufficient instrument time for each investigator. Furthermore, since BIAcore 2000 has an autosampler function that can be pre-programmed by the operator, many of the sample tests can be performed overnight. We will exploit this feature of BIAcore 2000 to our advantage. Any remaining available time on BIAcore 2000 will be allotted to other interested investigators with appropriate needs. As is manifest in the body of this application, we have presented greater detail regarding the optimal and equitable usage of BIAcore 2000. To address the second concern of the reviewers, each co-investigator has provided a brief but more complete background of her/his research interests and a greater detail of how BIAcore 2000 will be necessary for their research. We trust that with these changes and the fact that currently no such instrument is available in the entire Cincinnati area, the reviewers will view this amended application favorably.